In many scenarios, users require privacy protection for data content. For example, a blockchain technology (which is also referred to as a distributed ledger technology) is a decentralized distributed database technology, features decentralization, transparency, tamper-resistance, trustworthiness, etc., and is applicable to many application scenarios that require high data reliability. However, data such as transaction amounts of blockchain transactions can be exposed because full transaction data can be publicly queried. For another example, in a multi-party computation scenario, assume that user A holds data to be processed, and user B holds a data processing model. When the data to be processed is processed by using the data processing model, a value of the data to be processed can be exposed if user A sends the data to be processed to user B, and model parameters of the data processing model can be exposed if user B provides the data processing model to user A for use.